1. Field of the Invention
The present invention relates to a gasket member, a diaphragm, a flat panel speaker, a method of mounting the same flat panel speaker, and a method of assembling an electronic device, and more particularly to the method of mounting the flat panel speaker in a cabinet of a portable electronic device such as a foldable portable cellular phone or a like, the method of assembling the electronic device having the flat panel speaker, the gasket member to be used for the flat panel speaker and also serving as, for example, a screen component to protect a display panel and to support a diaphragm to emit a voice and to be used for prevention of the entry of a foreign matter such as dust or a like into the cabinet, the gasket-attached diaphragm constructed by attaching the gasket member to the diaphragm, and the flat panel speaker having the diaphragm and an actuator to vibrate the diaphragm.
2. Description of the Related Art
In recent years, due to high versatility of being usable even during movement of a user or while on a road, a portable electronic device such as a portable cellular phone is now in widespread use. Popularity has been gained by many users to a foldable and freely opened-closed type portable cellular phone, in particular, since the portable cellular phone can be housed in a compact state. The foldable portable cellular phone has become commercially practical which is so configured that, by using a two-axle hinge, one cabinet is allowed to freely rotate relative to another cabinet in a portion surrounding a rotational shaft mounted in a direction perpendicular to a rotational shaft used to open or close the cabinet.
In a portable cellular phone 101, as shown in FIGS. 14 and 15, an upper unit 102 and lower unit 103 are connected to each other by a two-axle hinge 104 and, on an upper cabinet 105 of the upper unit 102 are mounted a speaker section 106 to output a received voice and a display section 107 made up of a liquid crystal display device and, on a lower cabinet 108 of the lower unit 103 are mounted an operating section 109 made up of various operational keys, a microphone section 110 to receive a transmitting voice, and a voice outputting section 111 having a speaker.
Moreover, the display section 107, as shown in FIG. 16, has a liquid crystal display panel 112 and a backlight to supply illuminating light to the liquid crystal display panel 112, all of which are held by a holding frame 113 and are housed in the upper cabinet 105. Also, a screen component 114 to protect the liquid crystal display panel 112 is bonded to a front case 115 by using a double-faced adhesive sheet 116.
The portable cellular phone 101 having, in addition to its original telephone conversation function, a data communication function of receiving and transmitting electronic mail and/or of being connected to the Internet to browse home pages is widely used.
In the portable cellular phone 101 described above, for example, when a user executes a program downloaded from a site to enjoy a game, in order to hear a voice while seeing a screen of the display section 107, the portable cellular phone 101 is used with its cabinets opened.
However, the conventional portable cellular phone 101 has a problem. That is, when a user views a display screen of the display section 107 in a state in which the portable cellular phone is folded in a compact manner with the display screen faced toward a front, the user cannot hear a voice satisfactorily since a speaker of the voice outputting section 111 is hidden. Moreover, a user, when carrying out a telephone conversation, puts the speaker section 106 to his/her user's ear with the cabinet being opened, however, since a voice hole of the speaker section 106 is comparatively small, it is difficult for the user to put the voice hole on the ear exactly and the portable cellular phone 101 is displaced from a position of the voice hole, causing an insufficient amount of a voice and an unclear voice.
To solve this problem, in recent years, technology is proposed to be applied to a portable cellular phone (for voice outputting from a display screen, see Non-patent reference 1: “Nikkei Business”, the Nov. 1, 2004, Nikkei Business Publication Inc., p. 90) in which, for example, a screen component used to protect a display panel of a personal computer is to be used as a diaphragm making up a flat panel speaker of the portable cellular phone.
The flat panel speaker 201 employed in the conventional portable cellular phone 101 is mounted in a cabinet having a display section and, as shown in FIG. 17, is made of a transparent material of, for example, an acrylic resin and includes a diaphragm 202 also serving as a screen component to protect the liquid crystal display panel 112 and an actuator module 203 having a piezo-electric element which vibrates the diaphragm 202 for emission of sound waves.
The diaphragm 202, in its specified portion, is attached to the actuator module 203 so that vibrations are transferred from the actuator module 203 in a manner in which the diaphragm 202 strikes the actuator module 203 to come into physical contact and also is attached to the front case 115 making up another cabinet and having an aperture in its central portion to expose a display screen of the liquid crystal display panel 112 with the frame-shaped gasket member 204 used to prevent the entry of a foreign matter such as dust or a like interposed between the diaphragm 202 and the front case 115. The gasket member 204 is placed so as to surround the aperture of the front case 115 and is bonded, by using a frame-like double-faced adhesive sheet, to the diaphragm 202 and to a portion surrounding the aperture of the front case 115 respectively. Moreover, inside of the gasket member 204 is placed a frame-shaped dust preventing cushion component 205 to prevent the entry of dust into inside portions and to avoid the adhesion of dust to a surface of the liquid crystal display panel 112.
To mount the flat panel speaker 201 on the cabinet of the portable cellular phone 101, as the first step, the gasket member 204 is bonded to a circumferential portion of a rear of the diaphragm 202 by using the frame-like double-faced adhesive sheet and the double-faced adhesive sheet is pasted to a side of the gasket member 204 opposite to the diaphragm 202 and the gasket member 204 and the diaphragm 202 are sandwiched by a pair of protecting sheets from both sides to fabricate the gasket-attached diaphragm. Next, the protecting sheet on a rear side of the gasket-attached diaphragm is peeled off and the actuator module 203 is bonded to a specified portion of a rear of the diaphragm 202 by using, for example, a double-faced adhesive tape. Thereafter, on a rear side of the gasket-attached diaphragm is pasted an aperture-formed protecting sheet used to expose the actuator module 203.
Then, the aperture-formed protecting sheet on a rear side of the gasket-attached diaphragm is peeled off and, after positioning is performed on the diaphragm 202 relative to the position of the front case 115, the gasket member 204 is bonded to an edge of the aperture of the front case 115 using the double-faced adhesive sheet to attach the diaphragm 202 to a circumferential portion of the aperture of the front case 115. The dust preventing cushion component 205 is attached, in advance, to the holding frame 113 of the liquid crystal display panel 112 so as to be placed in a portion surrounding the liquid crystal display panel 112 and further a rear cover is assembled to be attached thereto. The front case 115 to which the diaphragm 202, actuator module 203, gasket member 204, or a like are attached and the rear cover to which the liquid crystal display panel 112, dust preventing cushion component 205, printed circuit board are attached are assembled together to be attached to each other.
The first problem to be solved is that, during a period from the process of attaching the actuator module to the diaphragm to the process of attaching the diaphragm to the front case, due to insufficient prevention of dust, dust enters from an aperture of the aperture-formed protecting sheet, causing the adhesion of dust to, for example, the diaphragm serving also as the screen component, which adversely affects an acoustic characteristic of the flat panel speaker and degrades displaying quality of the liquid crystal display panel.
The second problem to be solved is that peeling and re-pasting of the protecting sheet take much time and labor. That is, in the process of attaching the actuator module to the diaphragm, after the protecting sheet on the rear side of the gasket-attached diaphragm is peeled off, the actuator module is bonded to the rear of the diaphragm and, thereafter, additional following processes are required in which another aperture-formed protecting sheet having an aperture to expose the actuator module 203 is further pasted for prevention of dust to the rear side of the gasket-attached diaphragm to attach the diaphragm to the front case.